US1757498A - Dyeing with azo dyes - Google Patents
Dyeing with azo dyes Download PDFInfo
- Publication number
- US1757498A US1757498A US175926A US17592627A US1757498A US 1757498 A US1757498 A US 1757498A US 175926 A US175926 A US 175926A US 17592627 A US17592627 A US 17592627A US 1757498 A US1757498 A US 1757498A
- Authority
- US
- United States
- Prior art keywords
- acid
- naphthol
- sulphonic acid
- dyeing
- residue
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000004043 dyeing Methods 0.000 title description 12
- 239000000987 azo dye Substances 0.000 title 1
- 239000002253 acid Substances 0.000 description 22
- 150000008049 diazo compounds Chemical class 0.000 description 13
- 239000004627 regenerated cellulose Substances 0.000 description 9
- 239000000975 dye Substances 0.000 description 8
- 230000008878 coupling Effects 0.000 description 7
- 238000010168 coupling process Methods 0.000 description 7
- 238000005859 coupling reaction Methods 0.000 description 7
- ZYSOYLBBCYWEMB-UHFFFAOYSA-N 7-aminonaphthalen-1-ol Chemical compound C1=CC=C(O)C2=CC(N)=CC=C21 ZYSOYLBBCYWEMB-UHFFFAOYSA-N 0.000 description 6
- 229910052739 hydrogen Inorganic materials 0.000 description 6
- 239000001257 hydrogen Substances 0.000 description 6
- NYGZLYXAPMMJTE-UHFFFAOYSA-M metanil yellow Chemical group [Na+].[O-]S(=O)(=O)C1=CC=CC(N=NC=2C=CC(NC=3C=CC=CC=3)=CC=2)=C1 NYGZLYXAPMMJTE-UHFFFAOYSA-M 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 4
- 125000000664 diazo group Chemical group [N-]=[N+]=[*] 0.000 description 4
- 210000002268 wool Anatomy 0.000 description 4
- ZGNCICICEFKVNL-UHFFFAOYSA-K 3-methyl-4-pyrrolidin-1-ylbenzenediazonium;trichlorozinc(1-) Chemical compound [Cl-].[Cl-].[Cl-].[Zn+2].CC1=CC([N+]#N)=CC=C1N1CCCC1 ZGNCICICEFKVNL-UHFFFAOYSA-K 0.000 description 3
- 229920000297 Rayon Polymers 0.000 description 3
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 3
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 3
- 239000003086 colorant Substances 0.000 description 3
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 3
- 239000004289 sodium hydrogen sulphite Substances 0.000 description 3
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 150000004982 aromatic amines Chemical class 0.000 description 2
- 150000002431 hydrogen Chemical group 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 125000001624 naphthyl group Chemical group 0.000 description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 2
- 235000002639 sodium chloride Nutrition 0.000 description 2
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Chemical compound [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- RUFPHBVGCFYCNW-UHFFFAOYSA-N 1-naphthylamine Chemical compound C1=CC=C2C(N)=CC=CC2=C1 RUFPHBVGCFYCNW-UHFFFAOYSA-N 0.000 description 1
- QPKNFEVLZVJGBM-UHFFFAOYSA-N 2-aminonaphthalen-1-ol Chemical compound C1=CC=CC2=C(O)C(N)=CC=C21 QPKNFEVLZVJGBM-UHFFFAOYSA-N 0.000 description 1
- JBIJLHTVPXGSAM-UHFFFAOYSA-N 2-naphthylamine Chemical compound C1=CC=CC2=CC(N)=CC=C21 JBIJLHTVPXGSAM-UHFFFAOYSA-N 0.000 description 1
- JORRLNCNEFGAOY-UHFFFAOYSA-N 2-nitramidobenzenesulfonic acid Chemical compound OS(=O)(=O)C1=CC=CC=C1N[N+]([O-])=O JORRLNCNEFGAOY-UHFFFAOYSA-N 0.000 description 1
- XFDUHJPVQKIXHO-UHFFFAOYSA-N 3-aminobenzoic acid Chemical compound NC1=CC=CC(C(O)=O)=C1 XFDUHJPVQKIXHO-UHFFFAOYSA-N 0.000 description 1
- IHZXTIBMKNSJCJ-UHFFFAOYSA-N 3-{[(4-{[4-(dimethylamino)phenyl](4-{ethyl[(3-sulfophenyl)methyl]amino}phenyl)methylidene}cyclohexa-2,5-dien-1-ylidene)(ethyl)azaniumyl]methyl}benzene-1-sulfonate Chemical compound C=1C=C(C(=C2C=CC(C=C2)=[N+](C)C)C=2C=CC(=CC=2)N(CC)CC=2C=C(C=CC=2)S([O-])(=O)=O)C=CC=1N(CC)CC1=CC=CC(S(O)(=O)=O)=C1 IHZXTIBMKNSJCJ-UHFFFAOYSA-N 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 244000154870 Viola adunca Species 0.000 description 1
- 235000005811 Viola adunca Nutrition 0.000 description 1
- 235000013487 Viola odorata Nutrition 0.000 description 1
- 235000002254 Viola papilionacea Nutrition 0.000 description 1
- 150000001735 carboxylic acids Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- VMPITZXILSNTON-UHFFFAOYSA-N o-anisidine Chemical compound COC1=CC=CC=C1N VMPITZXILSNTON-UHFFFAOYSA-N 0.000 description 1
- BHAAPTBBJKJZER-UHFFFAOYSA-N p-anisidine Chemical compound COC1=CC=C(N)C=C1 BHAAPTBBJKJZER-UHFFFAOYSA-N 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- WPPDXAHGCGPUPK-UHFFFAOYSA-N red 2 Chemical compound C1=CC=CC=C1C(C1=CC=CC=C11)=C(C=2C=3C4=CC=C5C6=CC=C7C8=C(C=9C=CC=CC=9)C9=CC=CC=C9C(C=9C=CC=CC=9)=C8C8=CC=C(C6=C87)C(C=35)=CC=2)C4=C1C1=CC=CC=C1 WPPDXAHGCGPUPK-UHFFFAOYSA-N 0.000 description 1
- 238000005185 salting out Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 235000010288 sodium nitrite Nutrition 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- BDHFUVZGWQCTTF-UHFFFAOYSA-N sulfonic acid Chemical compound OS(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-N 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
- C09B33/00—Disazo and polyazo dyes of the types A->K<-B, A->B->K<-C, or the like, prepared by diazotising and coupling
- C09B33/02—Disazo dyes
- C09B33/08—Disazo dyes in which the coupling component is a hydroxy-amino compound
- C09B33/10—Disazo dyes in which the coupling component is a hydroxy-amino compound in which the coupling component is an amino naphthol
Definitions
- regenerated cellulose silks such as viscose silk, are dyed in level shades with the dyestuffs obtained by cou pling diazotized aromatic amines, their homologous derivatives and the sulphonic or carboxylic acids thereof, with 2-amino-8- naphthol-sulphonic acids including in this term their N substituted derivatives.
- the dyestuffs which we find to be applicable in our process of dyeing regenerated cellulose materials in even level shades, may be represented by the following compound and Y represents hydrogen or a coupled residue having the structure in which R is derived from a second diazo compound.
- the 2-amino-8-naphthol sul phonic acids which we find advantageous as starting materials inpreparing these dyestuffs are sulphonated 2-amino-8-naphthols having the characteristic structure wherein R represents hydrogen, an alkyl .from a second diazo compound.
- the monoazo dyestuffs may be represented by the following structurel formula.
- R represents the coupled residue of a sulphonated 2-amino-8-naphthol and R represents a residue derived from a diazo compound.
- the primary disazo dyestuffs may be represented by the generic structural formula wherein R represents the coupled residue of a sulphonated Q-aminO-S-naphthol, R represents aresidue derived from a diazo com- 6 pound and R represents a residue derived
- the monoazo dyestufis are obtained in the known manner by coupling in alkaline or in acid solution.
- useful disazo colours can be obtained by coupling one molecule' of a diazo compound on to a sulphonic acid of 2-amino-8-naphthol, or its N substituted derivatives, in an acid medium and afterwards combining the monoazo colour in an alkaline medium with one molecule of the same or a different diazo compound.
- the diazo compound obtained from 218 parts of para nitroanilineortho sulphonic acid with 69 parts of sodium nitrite in the known way is coupled with 315 parts of 2- phenylamino-8-naphthol-6-sulphonic acid in an acid medium.
- Themixture so obtained is made alkaline with sodium carbonate and to this is added a solution of the diazo compound obtained in the known way from 143 parts of a-naphthylamine.
- the coupling mixture is maintained alkaline until coupling is complete aften'whichthe dyestufl' is isolated by addition of salt. ' The structure is believed to be I sona on N.N ⁇
- 8 hydroxy-2 2-dinaphthylamine-3 6-disulphonic acid is similarly obtained from 2- amino-8-naphthol-3 6-sulphonic acid, sodium bisulphite and ,B-naphthyIamine.
- Arylamine diazotized Aminonaphthol coupled Coupling medium Shade gf p-anisidine 2-amino-8-naphthol-6-sulphonic acid Alkaline Reddish-brown o-anisidine 2-amino-8-naphthoI-G-sulphonic acid Alkaline Red 2:5-dichloroaniline 2-phenylamino-s naplithol-S-sulphonic acid Alkaline Brown S-nitro-o-anisidine Z-phenylamino-S-naphthol-6-sulphonic acid Acid Deep blue N aphthionic acid 2-pheny1arnino-8-naphthol-Gsulphonic acid Acid Violet brown z-chloro-p-toluidine-dsulphonic acid 2-phenylarnino-B-naphthol-S-sulphonic acid Alkaline Brown Aniline 8-hydroxy-2:l-dinaphthylamine-G-sulph
- R represents the coupled residue of a sulphonated 2-amino-8-naphthol having the characteristic structure NHR wherein R represents hydrogen, an alkyl group or a phenyl or naphthyl residue, R represents a residue from a diazo compound and Y represents hydrogen or the structure in which R is a residue from a second diazo compound.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Coloring (AREA)
Description
atented W ii JAMES BADDILEY, PERCY CIEEOBLEY, AND RAINALD BRIGHTMAN, 01E BLAGMIIEY, MAN'- CHESTER, ENGLAND, ASSIGNOBS T0 BRITISH: DYESTUJEFS CORPORATION LIMITED, 015 MANCHESTER, ENGLAND, A COMPANY OF GREAT BRII'JETIN' AND IRELAND prisms wrrn azo n'rns No Drawing". Application filed March 16, 1927, Serial No. 175,926, and in Great Britain September PI, 1926.
By this invention regenerated cellulose silks, such as viscose silk, are dyed in level shades with the dyestuffs obtained by cou pling diazotized aromatic amines, their homologous derivatives and the sulphonic or carboxylic acids thereof, with 2-amino-8- naphthol-sulphonic acids including in this term their N substituted derivatives.
Some of these dyestuffs are already known, and have been described for dyeing wool, particularly for the production on wool of dyeings which are fast to milling, but it was not foreseen that these dyestufis could be used for dyeing regenerated cellulose silks. It is well known that the animal fibres such as wool are quite different from the cellulose fibres both in chemical and in physical properties and it is therefore all the more surprising that these simple wool colours should have value for dyeing regenerated cellulose silks.
We do not limit ourselves to the use of the monoazo colours but we also include within the scope of our invention certain primary disazo dyes. The dyestuffs which we find to be applicable in our process of dyeing regenerated cellulose materials in even level shades, may be represented by the following compound and Y represents hydrogen or a coupled residue having the structure in which R is derived from a second diazo compound. The 2-amino-8-naphthol sul phonic acids which we find advantageous as starting materials inpreparing these dyestuffs are sulphonated 2-amino-8-naphthols having the characteristic structure wherein R represents hydrogen, an alkyl .from a second diazo compound.
group or a phenyl or naphthyl residue. The monoazo dyestuffs may be represented by the following structurel formula.
wherein It, represents the coupled residue of a sulphonated 2-amino-8-naphthol and R represents a residue derived from a diazo compound. The primary disazo dyestuffs may be represented by the generic structural formula wherein R represents the coupled residue of a sulphonated Q-aminO-S-naphthol, R represents aresidue derived from a diazo com- 6 pound and R represents a residue derived The monoazo dyestufis are obtained in the known manner by coupling in alkaline or in acid solution. We have found that useful disazo colours can be obtained by coupling one molecule' of a diazo compound on to a sulphonic acid of 2-amino-8-naphthol, or its N substituted derivatives, in an acid medium and afterwards combining the monoazo colour in an alkaline medium with one molecule of the same or a different diazo compound. For example the diazo compound obtained from 218 parts of para nitroanilineortho sulphonic acid with 69 parts of sodium nitrite in the known way is coupled with 315 parts of 2- phenylamino-8-naphthol-6-sulphonic acid in an acid medium. Themixture so obtainedis made alkaline with sodium carbonate and to this is added a solution of the diazo compound obtained in the known way from 143 parts of a-naphthylamine. The coupling mixture is maintained alkaline until coupling is complete aften'whichthe dyestufl' is isolated by addition of salt. 'The structure is believed to be I sona on N.N\
N O CnmNH N :N
It forms a black powder which dyes viscose silk a blue violet shade. If 8-hydroxy-2-2- dinaphthylamine-6sulphonic acid be used in place of 2-phenylamino-8-naphthol-6-sulphonic acid in the above example the dyestufi's obtained dyes viscose silk a blue shade.
8 hydroxy-Q 2- dinaphthylamine G-sulphonic acid is prepared by heating 2-amino- 8-naphthol-(i-sulphonic acid with sodium bisulphite and B-naphthylamine. When the reaction is completed, the mixture is diluted and the product precipitated by the addition of common salt, filtered oil", dissolved in soda and filtered from unchanged B-naphthylaminc-and any ,BB-dinaphthylamine which may be present. The S-hydroxy-Q 2-dinaphthylamine-G-sulphonic acid is then precipitated as a white or greyish substance by acidifying the filtrate. Its probable structure is:
8 hydroxy-2 2-dinaphthylamine-3 6-disulphonic acid is similarly obtained from 2- amino-8-naphthol-3 6-sulphonic acid, sodium bisulphite and ,B-naphthyIamine.
For the preparation of 8-hydroXy-2: 1-dinaphthylamine- 6-sulphonic acid, 2-amino-8- naphthol-tS-sulphonic acid is heated with sodium bisulphite and a-n aphthylamine. After salting out the productas above described, the'sol-id is Washed with hydrochloric acid to remove unchanged a-naphtliylamine, and is then ready for use, no aa-(ll-' naphthylamine being formed. Its structure is probably SOaH- NHCeHu 100 parts of the regenerated cellulose silk goods are entered into the bath warm, after which the bath is heated nearly to the boil and dyeing is allowed to proceed nearly at the boil for about 1 hour. The goods are then removed, rinsed and dried. The resulting dyeing is a level deep brown shade, fast to washing, alkalis and to light.
The range of shades obtainable with monoazo dyes alone is further illustrated by the examples in the following table.
Arylamine diazotized Aminonaphthol coupled Coupling medium Shade gf p-anisidine 2-amino-8-naphthol-6-sulphonic acid Alkaline Reddish-brown o-anisidine 2-amino-8-naphthoI-G-sulphonic acid Alkaline Red 2:5-dichloroaniline 2-phenylamino-s naplithol-S-sulphonic acid Alkaline Brown S-nitro-o-anisidine Z-phenylamino-S-naphthol-6-sulphonic acid Acid Deep blue N aphthionic acid 2-pheny1arnino-8-naphthol-Gsulphonic acid Acid Violet brown z-chloro-p-toluidine-dsulphonic acid 2-phenylarnino-B-naphthol-S-sulphonic acid Alkaline Brown Aniline 8-hydroxy-2:l-dinaphthylamine-G-sulphonic acid Alkaline Brown m-aminobenzoic acid 8-hydroxy-2:2-dinaphthylaminc-G-sulphonic acid Alkaline Brown 2:5dichloroaniline 8-hydroxy2:2-'dinaphthylamine-3z6-disulphonic acid Acid Red A-chloro-o-anisidine 8-hydroxy-2:2'-dinaplitliylamine fizfi-disulphonic acid Alkaline Bordeaux Dehydrothio-p-toluidinesulphonic acid Z-Oanisoylamino-S-naphthol-G-sulphonic acid Alkaline Brown Dehydrothio-p-toluidinesulphonic acid 2-phenylamino-Ei-naphthol-fi-sulphonic acid Alkaline Brown p-chloroaniliue 2-p-chlorophenylamino-8-naphthol-fi-sulphonic acid Alkaline Light brown Dehydrothiotoluidinesulphonic acid 2 dinitroiihen y lamino) -8- naphthol -6- sulphonic Alkaline Reddish brown Dehydrothiotoluidinesulphonic acid 8-hydroxy-2:2- iinaphthyl-amino-o-sulphonic acid Alkaline Brown i:4-nitroaminodiphenylsulphide v 8-hydroxy-2:2'-dinaphthyl-amine-3:G-disulphonic acid Alkaline Brown p aminoacetaniline 2-ethylamino-B-nahpthol-dsulphonic acid Alkaline Reddish brown Dianisidineoxamic acid 2-pl1enylamino-8-naphthol-G-sulphonic acid Alkaline Reddish blue What we claim and desire to secure by Letters Patent is 1. The process of dyeing regenerated cellulose materials in level shades comprising the application of dyes having the probable formula YR N=NR wherein R represents the coupled residue of a sulphonated 2-amino8-naphthol, R represents a residue from a diazo compound and Y represents hydrogen or the structure N=N-R in which R is the residue from a second diazo compound.
2. The process of dyeing regenerated cellulose materials in level shades comprising the application of dyes having the following probable structural formula wherein R represents the coupled residue of a sulphonated 2-amino-8-naphthol having the characteristic structure NHR wherein R represents hydrogen, an alkyl group or a phenyl or naphthyl residue, R represents a residue from a diazo compound and Y represents hydrogen or the structure in which R is a residue from a second diazo compound.
3. The process of dyeing regenerated cellulose materials in level shades comprising the application of dyes having the following probable structural formula whereinlii represents the coupled'residue of a 2-amino-8-naphthol-6-sulphonic acid, R represents a residue from a diazo compound and Y represents hydrogen or the structural formula in which R is a residue from a second diazo compound.
4. vThe process of dyeing regenerated cellulose materials in level shades comprising the application of monoazo dyes obtained by coupling a Q-amino-8-naphthol-6-su1phonic acid having the characteristic structure HOaS tures.
JAMES BADDILEY.w PERCY GHORLEY. I RAINALD BRIGHTMAN.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1757498X | 1926-09-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
US1757498A true US1757498A (en) | 1930-05-06 |
Family
ID=10889979
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US175926A Expired - Lifetime US1757498A (en) | 1926-09-07 | 1927-03-16 | Dyeing with azo dyes |
Country Status (1)
Country | Link |
---|---|
US (1) | US1757498A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2553261A (en) * | 1946-12-20 | 1951-05-15 | Sandoz Ltd | Hydroxy-acylamino azo dyestuffs of the naphthalene series and a process of making same |
-
1927
- 1927-03-16 US US175926A patent/US1757498A/en not_active Expired - Lifetime
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2553261A (en) * | 1946-12-20 | 1951-05-15 | Sandoz Ltd | Hydroxy-acylamino azo dyestuffs of the naphthalene series and a process of making same |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2194927A (en) | Azo compound | |
US2314023A (en) | Substantive azo dyestuffs and process of making same | |
US1867451A (en) | Azo-dyestuffs and process of making same | |
US2268919A (en) | Polyazo dyestuffs and process of making same | |
US2056539A (en) | Azo-dyestuffs and process of making same | |
US1757498A (en) | Dyeing with azo dyes | |
US2241795A (en) | Acid azo dyestuffs | |
US2411646A (en) | Disazo dyestuffs and process of making same | |
US2196028A (en) | Azo dyestuffs | |
US2077322A (en) | Process for the manufacture of azo dyestuffs for esters of cellulose and azo dyestuffs obtained therefrom | |
US2305747A (en) | Complex chromium compounds of ortho-hydroxyazo dyestuffs and process of making same | |
US2248151A (en) | Production of substantive azo dyestuffs | |
US2157877A (en) | Polyazo dyestuffs | |
US1857244A (en) | New monoazodyestuffs | |
US2066985A (en) | Water-insoluble azodyestuffs | |
US2067726A (en) | Water insoluble monoazo dyes | |
US2092076A (en) | Disazo dyestuffs and their production | |
US2423542A (en) | Monoazo dyes | |
US2717891A (en) | Hydroxy quinoline trisazo-dyestuffs | |
US2083619A (en) | Method for the preparation of azo dyes | |
US1982332A (en) | Azodyestuffs | |
US2030214A (en) | Azo dyes and methods for their preparation | |
US2383264A (en) | Azo dyestuffs from 5-amino coumaran | |
US1933585A (en) | Azo dyes and their production | |
US2158283A (en) | Dyestuffs |